I'm pretty sure the title describes this one... The Segway technology married to a seat so that someone whose legs don't work (or doesn't have legs) can still enjoy Segway!
http://www.youtube.com/watch?v=Iv_SfonG4w4
Cool but the http://www.ibotnow.com/ is more impressive and invented by the inventor of the segway. Best part is that it can increase hight and go up stairs!